Advancing Breast Cancer Research in Japan Using EHR-Derived Real-World Data
Author(s)
Blythe Adamson, MPH, PhD1, Dionne Ng, BA2, Harlan Pittell, PhD1, Arun Sujenthiran, MD3, Eri Tajima, MS2.
1Flatiron Health, New York, NY, USA, 2Flatiron Health K.K., Tokyo, Japan, 3Flatiron Health UK, London, United Kingdom.
1Flatiron Health, New York, NY, USA, 2Flatiron Health K.K., Tokyo, Japan, 3Flatiron Health UK, London, United Kingdom.
Presentation Documents
OBJECTIVES: Breast cancer is the most commonly diagnosed cancer among women in Japan, with significant heterogeneity in treatment patterns and outcomes. Real-world evidence (RWE) is critical to understanding treatments and outcomes in routine clinical practice. Here we characterize a growing, novel cohort as a comprehensive, deidentified resource to evaluate treatment effectiveness for women with breast cancer in Japan.
METHODS: The Flatiron Health Japan Breast Cancer dataset is derived from deidentified electronic health records (EHRs) collected from routine oncology care in Japan. The dataset includes structured and unstructured data curated through technology-enabled abstraction. Key variables include demographics, clinical characteristics, biomarker testing, treatments, and death. Data quality and completeness were assessed to ensure reliability for research purposes.
RESULTS: The cohort, now prospectively being followed, included 956 patients diagnosed with breast cancer between January 11, 2011, and September 31, 2024. Median age at diagnosis was 54 (IQR, 46-65). Group stage at initial diagnosis was 26% Stage 0-1, 47% Stage II, 18% Stage III, 10% Stage IV, and 5% unknown/not documented. 20% of patients developed metastatic disease with a recorded diagnosis date. Histology was known for 99% of patients with 88% having invasive ductal carcinoma. Among patients treated with systemic therapy, 99% of patients had full or near-full functional status (ECOG 0-1). Radiotherapy was used in 50%, surgical resection in 87%, and genetic testing for HER2 in 99% of patients. The dataset demonstrated high completeness, with minimal missing data for key clinical variables.
CONCLUSIONS: The Japan Breast Cancer dataset provides valuable insights into real-world experiences of women with breast cancer in Japan. Analysis in a trusted research environment enables a secure and robust platform for generating actionable RWE for research and policy development in Japan. Future research will focus on comparative effectiveness studies and cross-country analyses to advance global breast cancer care.
METHODS: The Flatiron Health Japan Breast Cancer dataset is derived from deidentified electronic health records (EHRs) collected from routine oncology care in Japan. The dataset includes structured and unstructured data curated through technology-enabled abstraction. Key variables include demographics, clinical characteristics, biomarker testing, treatments, and death. Data quality and completeness were assessed to ensure reliability for research purposes.
RESULTS: The cohort, now prospectively being followed, included 956 patients diagnosed with breast cancer between January 11, 2011, and September 31, 2024. Median age at diagnosis was 54 (IQR, 46-65). Group stage at initial diagnosis was 26% Stage 0-1, 47% Stage II, 18% Stage III, 10% Stage IV, and 5% unknown/not documented. 20% of patients developed metastatic disease with a recorded diagnosis date. Histology was known for 99% of patients with 88% having invasive ductal carcinoma. Among patients treated with systemic therapy, 99% of patients had full or near-full functional status (ECOG 0-1). Radiotherapy was used in 50%, surgical resection in 87%, and genetic testing for HER2 in 99% of patients. The dataset demonstrated high completeness, with minimal missing data for key clinical variables.
CONCLUSIONS: The Japan Breast Cancer dataset provides valuable insights into real-world experiences of women with breast cancer in Japan. Analysis in a trusted research environment enables a secure and robust platform for generating actionable RWE for research and policy development in Japan. Future research will focus on comparative effectiveness studies and cross-country analyses to advance global breast cancer care.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
RWD143
Topic
Real World Data & Information Systems
Topic Subcategory
Health & Insurance Records Systems
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, SDC: Oncology